Characteristic

Rest

15° tilt

Change after 15° tilt


Delirium, n = 5

No delirium, n = 9

Delirium, n = 5

No delirium, n = 9

Delirium, n = 5

No delirium, n = 9


Frequency Domain Measures

PSD RRI

2400

174

6213^{†}

141

− 202

13

(350–30,075)

(16–20,659)

(148–22,462)

(46–19,083)

(−7612–8015)

(− 1576–439)

LFnuRRI

21

29

23^{††}

39

2

7

(11–62)

(17–57)

(9–65)

(25–62)

(− 28–4)

(−14–16)

HFnuRRI

79

71

77^{††}

61

−2

−7

(39–89)

(43–83)

(35–91)

(38–75)

(− 4–28)

(− 16–14)

LFabsRRI (ms^{2})

419^{†}

27

854

29

−44

12

(87–11,813)

(5–5986)

(27–11,579)

(10–5943)

(−234–860)

(− 69–163)

HFabsRRI (ms^{2})

1804

88

5267^{†}

39

1

4

(86–7371)

(8–14,150)

(87–9161)

(12–11,365)

(− 1150–7071)

(− 2785–130)

LF/HF ratio

0.3

0.4

0.3^{†}

0.5

0

0.1

(0.1–1.6)

(0.2–1.3)

(0.1–1.9)

(0.3–1.4)

(− 0.7–0.3)

(− 0.5–0.8)

Time Domain Measures

SDNN (ms)

51^{†}

25

36

22

−15 ^{b}

0

(27–227)

(8–69)

(17–174)

(13–63)

(− 54  5)

(− 12–16)

pNN50 (%)

11^{†}

1

9

2

−1

0

(3–68)

(0–36)

(0–86)

(0–20)

(− 10–18)

(− 16–16)

RMSSD (ms)

36

20

30

30

−9

8

(15–151)

(7–75)

(27–33)

(19–43)

(− 120–19)

(−44–23)

 LFnuRRI and HFnuRRI = low frequency and high frequency power in normalized units; LF or HF/(Total PowerVFL(very low frequency) × 100; LFabsRRI and HFabsRRI = power in high frequency and low frequency range in absolute values, respectively; LF/HF = ratio low frequency power/high frequency power; SDNN = Standard Deviation of all NN intervals; pNN50 = NN50 count divided by the total number of all NN intervals; NN50 = number of interval differences of successive NN intervals greater than 50 ms; RMSSD = Root of the Mean of the Sum of Squares of Differences between adjacent NN intervals; NN intervals = normaltonormal intervals; BRS = Baroreceptor reflex sensibility
 ^{†}p = 0.06, MannWhitney test
 ^{††}p = 0.08, compared with controls
 ^{a} Values are medians and total range obtained from registration during sequences of four minutes at rest, and after tilt to 15°. Change after 15° tilt is compared to resting values
 ^{b}p = 0.01, MannWhitney test